Editing bound paragraph in post editor causes "Site Updated" message to appear

[artemiomorales]

Description

In the post editor, if one modifies a block connected to post metadata via block bindings, a "Site Updated" notification displays when saving the post, which is incorrect.

First raised in #61811 and a part of the block bindings iteration for WordPress 6.6.

Step-by-step reproduction instructions

1. Register post meta by adding this snippet to your theme's functions.php

add_action( 'init', 'test_block_bindings' );

function test_block_bindings() {
	register_meta(
		'post',
		'text_field',
		array(
			'show_in_rest'      => true,
			'single'            => true,
			'type'              => 'string',
			'default'           => 'default text value',
		)
	);
}

2. In the post editor, add a paragraph block bound to the custom field using the Code Editor

<!-- wp:paragraph {"metadata":{"bindings":{"content":{"source":"core/post-meta","args":{"key":"text_field"}}}}} -->
<p>Paragraph content</p>
<!-- /wp:paragraph -->

3. Press the Save button.
4. Notice that the "Site Updated" message appears, despite the fact that you made no site-wide changes.

Screenshots, screen recording, code snippet

Environment info

• Gutenberg Release Candidate 18.5

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes